Objective To compare preventive effect between continuous dissecting suture and traditional interrupted suture, silver ion dressing and traditional dressing, on the incisional surgical site infection (SSI) after ostomy for colorectal surgery, and to explore the influencing factors of SSI. Methods ① Sixty patients underwent the firstly elective open ostomy for colorectal surgery, who were treated in Department of Colorectal Tumor Surgery and Department of Colorectal&Hernial Minimally Invasive Surgery of Shengjing Hospital from Mar. 2015 to Jan. 2016, were collected to equivalently divided into continuous dissecting suture group and traditional interrupted suture group randomly. ② Twenty-seven patients with emergency open ostomy for colorectal surgery, who were treated in Department of Colorectal Tumor Surgery and Department of Colorectal&Hernial Minimally Invasive Surgery of Shengjing Hospital from Jan. 2009 to Jun. 2015, as well as 33 patients with elective open ostomy for colorectal surgery, who were treated in the same 2 Departments from Jul. 2015 to May. 2016, were collected to equivalently divided into silver ion dressing group and traditional dressing group. ③ Clinical data of 184 patients with elective open ostomy for colorectal surgery who were treated in Department of Colorectal Tumor Surgery and Department of Colorectal&Hernial Minimally Invasive Surgery of Shengjing Hospital from Jan. 2009 to May. 2016 were collected to analyze the influencing factors of SSI after elective open ostomy for colorectal surgery. Results ① There was no significant difference in the incidence of SSI between continuous dissecting suture group (3.3%, 1/30) and traditional interrupted suture group (16.7%, 5/30), P=0.085. ② The incidence of SSI in silver ion dressing group (6.7%, 2/30) was significantly lower than that of traditional dressing group (30.0%, 9/30), P=0.020. ③ There were 28 patients (15.2%) of the 184 elective patients and 11 patients (40.7%) of the 27 emergency patients suffered from SSI after open ostomy for colorectal surgery, and the incidence of SSI in elective surgery group was lower than that of emergency surgery group (P=0.001). ④ Results of logistic regression model showed that, patients with body mass index (BMI) <25 kg/m2 had lower risk of SSI than patients with BMI≥25 kg/m2(OR=0.383, P=0.023), patients received permanent colostomy had higher risk of SSI than patients received protective ileostomy (OR=4.370, P=0.004), patients underwent Mile’s surgery had higher risk of SSI than patients received distal anastomosis (OR=4.406, P=0.005). Conclusions The ostomy is a high risk factor for incisional SSI after elective open ostomy for colorectal surgery, especially for the obesity patients and patients who receive colostomy. The using of silver ion dressing play an important role in preventing the incisional SSI.